Evening star. [volume] (Washington, D.C.) 1854-1972, 1887-12-06

gent aysIenDOf experimentation have attained re-
suits that constitute the payements OF Washing
ton one OF the great advantages and attrac-
lions OF the city, and establish Them as models
OF construction under similar circumstances else
where A mass OF detailed Information upon the
the reports Col Grimm on the subject OF streets
There are four pavements now In service In WASH
ington which are regarded as having special adap-
varying circumstances.
The two street payements, VIZ the standard
asphalt" with a 6-inch hydraulic base, and IL
inch wearing surface, and the cOal-tar distillate
or asphalt, with 4-inch btuminous base ana p
inch wearing surface, represent tine survivors Of
the considerable number OF composite payemeDts
heretofore tried II Is the standard asphalt
with which the greater part OF the street surface
has been paved. The asphalt block has been found
very satisfactory for streets OF light traffic and
recent improvements In the manufacture OF the
blocks giving them greater density and uniformity
OF structure, have enhanced their practical value
The stOne-6lock pavement Is only used upon
streets OF heavy TRAFFIC and In the vicinity OF COM
merctal establishments for the freighting OF heavy
loads In q lew instances, also, II mas been pre-
ferre for the paving OF the sleeper street grades
The appropriation act for the last year limited
me 70 - ne sSu .s ward s
had heretofore been paid under contract i0r them
Both the street pavements described are OF q
uIars OF relative advantage. The company re-
fused 70 make contract for the standard asphalt
pavement a. 81. and submitted modified propo-
sutton under which she six-inch by raunc base
should be reduced 70 four incnes and the strength
OF the concrete increased by the admixture or
Portland cement with the native hydraulic In
such proportion as should make the four-inch base
In eject as rigid and enduring as the SIX.
This the company were prepared to lay at s.,
and contract for the paving OF q Few streets was
made with hem 70 that elect IL 10 manifest
that II q 4-tnch bitumin0uS base Is ample TO sup
port the Jrnfic and the experience OF twelve years
has SHOWN that it Is. 4-inch hydraulic base might
at least be expected 20 answer the same purpose,
especially II les composition were so mudffed as 70
warrant the judgment that tia ultimate retstence
would equal that OF the six as formerly laid A
certain objection to this action OF the Commits
s,oners has been expressed, and further stlpula-
ton was introduced In the last appropriation act
calling for the retention Of the fun depth OF 9
inchea
It is obvious that II o depth OF base OF four
inches 10 enough, Q greater thickness v only an
unnecessary EXPENSE, and as In all Cases the con-
struction OF these payements Is conducted with
great care under rigfd inspection. with proper
ions exactly deterintned and 'he qualify a. the
materials thoroughly ascertatnco, aud a. The COZ
tractor u Responsible for the maintenance Of the
pavement for nve years. the only eject Of nxtng
Sue dimensions OF the pavement In the appropriar
ton act II increase the COST Of construction The
general provision Of law thai new pavelnents shall
Dc In no reapact inferior 70 The best laid being all
that 10 legally necessary 70 regulate shsar dura-
Tue rssuir hss been to deprive the District OF the
opportunity OF securing the standard asphalt with
watch the greater proportion Of the streets Of
Wxshington h paved and 70 compel reliance solcly
upon the coal Tar and disttllaIe pavementa, whick
b reAs0n q the lower cost OF the coa Tar ana Of
tie inch nlsnmin01s basas can b laid within ths
Ehiis ths dissiIIats psvsnsas y rscognazsd =